The microphones on most video cameras are programmed to adjust their own sound levels: they take whatever they hear and boost it to a constant, listenable level. Unfortunately, if they hear crowd noise around you, they boost that. Traffic noise, sirens—it all gets boosted.
In fact, if the camera mic hears nothing, it boosts that too. In an interview where the subject is too far from the mic, the camera will crank up every hint of sound between you and them, creating a big, echoey overlay of room noise.
If you’re as close to your subject as you should be … Read the rest
Steve Stockman is a writer/ producer/ director in Los Angeles. How to Shoot Video That Doesn't Suck, available in 9 languages, is the best selling video how-to book in the world. You can find the updated (2017) edition from Workman Publishing wherever you get books, ebooks or audiobooks. 
